亲水胶体对大豆、花生双蛋白凝胶持水性的影响及机制探究

Effect of Hydrocolloid on the Water Holding Capacity of Soybean and Peanut Mixed Protein Gel and Its Mechanism

以亚麻籽胶、魔芋胶、瓜尔豆胶等亲水胶体及大豆分离蛋白、花生蛋白为原料,经高速斩拌,制备大豆、花生双蛋白凝胶体系。研究亲水胶体的种类及添加量对双蛋白凝胶的持水性及含水量的影响,并通过测定凝胶微观结构、蛋白质二级结构及水分分布状态,对其机制进行探究。实验结果表明:添加1.5%亚麻籽胶的凝胶持水性最佳,为97.15%;添加0.9%亚麻籽胶时凝胶含水量最高为63.49%;在物理结构上,亲水胶体通过吸水膨胀均匀分散在致密的蛋白网络结构中;在化学结构上,亲水胶体增加凝胶体系中蛋白质无规则卷曲含量,降低其β-转角含量;这些物理化学变化使凝胶中可迁移含水量上升,自由含水量降低,宏观上则表现为凝胶持水性及含水量相对于空白组得到提升,质构随之变化。

Using hydrocolloids such as linseed gum,konjac gum,guar gum and soy protein isolate and peanut protein as raw materials,the soybean and peanut double protein gel system is prepared by high-speed chopping.The effect of the type and amount of hydrocolloids on the water holding capacity and water content of the double protein gel was studied,and the mechanism was explored by measuring the gel microstructure,protein secondary structure and water distribution state.The experimental results show that the gel with 1.5%linseed gum has the best water holding capacity,which is 97.15%.When 0.9%linseed gum is added,the maximum water content of the gel is 63.49%.In physical structure,the hydrocolloids are evenly dispersed in dense protein network structure through water absorption and expansion.In chemical structure,hydrocolloids increase the irregular curl content of the protein in the gel system and reduce itsβ-turn content.These physical and chemical changes increase the mobile water content in the gel and decrease the free water content.Macroscopically,the water holding capacity and water content of the gel are improved compared with the blank group,and the texture changes accordingly.